Background: http://photo.net/beginner-photography-q ... um/00brfTt
TL;DR
The cam only adjusts shutter speed to your exposure compensation automatically in PSA. In M, you got to do it yourself.
Meaning if we are using M, the bracketing feature has no effect at all, since shutter speed is not adjust by user/dcc. Thus, it's not possible to shoot full manual HDR unless not using the bracketing tool but adjusting shutter speed yourself.

[Feature request] Add shutter speed to bracketing please

I concur. I shoot artwork under static lighting and use an external light meter to calculate shutter speed, etc. Being able to bracket multiple shutter speeds around these manual settings would be a great addition to the program.